16221749 has 2 divisors, whose sum is σ = 16221750. Its totient is φ = 16221748.

The previous prime is 16221743. The next prime is 16221761. The reversal of 16221749 is 94712261.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14303524 + 1918225 = 3782^2 + 1385^2 .

It is a cyclic number.

It is not a de Polignac number, because 16221749 - 2⁸ = 16221493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16221743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8110874 + 8110875.

It is an arithmetic number, because the mean of its divisors is an integer number (8110875).

Almost surely, 2^16221749 is an apocalyptic number.

It is an amenable number.

16221749 is a deficient number, since it is larger than the sum of its proper divisors (1).

16221749 is an equidigital number, since it uses as much as digits as its factorization.

16221749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 32.

The square root of 16221749 is about 4027.6232445451. The cubic root of 16221749 is about 253.1429823937.

The spelling of 16221749 in words is "sixteen million, two hundred twenty-one thousand, seven hundred forty-nine".